Sound reproducing diaphragm



Aug. 18, 1931. LE ROY w. STAUNTON 1,319,559

SOUND REPRODUCIN'G' DIAPHRAGM Filed June 30, 1926 3 Sheets-Sheet l IN VEN TOR.

BY w ATTORNEYS Aug. 18, 1931. LE RO Y w. STAUNTON SOUND REPRODUCING DIAPHRAGM 3 Sheets-Sheet Filed June 30, 1926 4 D INVENTOR. Wx kumfoia A TTORNEYS.

Aug. 18, 1931.

LE ROY w. STAUNTON SOUND REPRODUCING DIAPHRAGM 1926 3 Sheets-Sheet 3 Filed June 30 INVENTOR.

Z? BY ATTORNEY Patented Aug. 18, 1931 I so T- TIE is LE ROY w. STAUNT'ON, or JACKSON HEIGHTS, new YORK, ASSIGNOR T BRANDES 1 LABORATORIES, me, or NEWARK, NEWJERSEY, A CORPORATION on NEW JERSEY SOUNDIBEPRODUOING DIAPHRAGM Application med June 30,

i l My invention relates broadly to sound refB' riphery.

producing diaphragms, and more particularly' to a sound reproducing diaphragm of thin sheet material having. an ellipticalpe- -Oneof the objects of myinvention is to provide a sound reproducing diaphragm capabl'e of reproducing the entire range of musical-notes Enormally received in radio broadcast reception.

, Another ohjectof'iny invention is-toprovide an-elliptioal conical shapedsound reproducing diaphragm into which stresses 'areintroducedfor eliminating the flabbiness of the diaphragm and-to avoid'the rattling .ofrthe material of the diaphragm-during conditions Ofrapid vibration.

Anotherobjectof my invention is to proof audio frequency notes.

vide -a construction of conical diaphragm having an elliptical periphery in which the proper characteristic of 'stifleners-to thin sheet. fibrous material may be introduced for securing efficient-reproduction of soundover the entire range of audio frequency .notes normally presentin broadcast reception. 1

I Still another object of my inventionis to provide a construction of elliptical conical diaphragm to whichsound vibrations may be imparted to a central point for the reproduction of sound emanating throughout the area of the diaphragm. from the central point .thereof theedge -.of the. diaphragm being substantially free forthe reproduction of soundover the entire musical scale.

, A still further object of my invention is to provide adiaphragm construction o'felohgated shape for the prevention of an'overamplification of low frequencynotes and the more uniform production of the entirerange Other an'dIfurther objects of my invention will be understood fromthe specification "hereinafter following by reference to the accompanying drawings in-which: 1 iFigure'llis a 'plan view ofthe elliptical conical diaphragm of'my invention; Fig. 2

. isa side view of the ellipticalconical diaphragm of. myinvention .showing the dia- E hragm in the processof manufacture where stressesaare being-introduced by :pressing the v.phragm on line 10-10 of Fig. 8.

1926. Serial No. 119,768.

diaphragm against its supporting surface; Fig. 3 is a perspective view illustrating the method of manufacture of the elliptical conical shape diaphragm of my invention; Fig. 4 is a plan View of an elliptical diaphragm of flat formation employing the-principles of my invention; Fig. 5- shows the application of an elliptical flat diaphragm to an electro-magnetic driving apparatus and the construction I may employ for supporting the diaphragm at substantially the central point'thereof; Fig. (Sis a perspective view illustrating the elliptical shaped diaphragm of my invention; Fig. 7 is a theoretical diagram illustrating the advantages of the con- ..terial me. be brou ht about b employin y g y g an elliptical shape diaphragm formed in the shape ofa cone.

cal conical diaphragm vis substantially ree floating, and substantially free to vibrate,

while the sound vibrations are imparted to the diaphragm at substantially the center thereof. The vibrations are initiated at substantially the center of the elliptical diaphragm and emanate outwardly to the edge. Thezoval or elliptical shape results in a more even balance between the high notes and the low notes-rather than the preponderance of low notes as normally exists in perfectly round diaphragms.

"I construct the diaphragm of my present invention from thin sheet fibrousmaterial a I whichis rounded into the shape of an ellipti- -cal1cone.

The-base of-the cone is normally bowed out of a plane and by pushing the tip 'downwardlyuntil the perimeter lies in. the same plane, stresses are thrown into the .80 The edge of the elli tifibrous material of the cone stiffening the entire sound reproducing diaphragm and slightly raising the natural period thereby removing the disagreeable rattle that is present in the reproduction of certain types of music in cone diaphragms of circular shape.

Referring to the drawings in more detail the elliptical cone shaped diaphragm 1 has been illustrated in plan view in Fig. 1 with its edges joined at 2 and having a center 3.

In Fig. 2 I have shown the perimeter of the elliptical conical diaphragm 1 normally bowed outwardly at a from the plane surface 5. In order that stresses may be introduced into the thin sheet material of the diaphragm 1, pressure is applied to the tip of the elliptical conical diaphragm introducing the forces illustrated at 6. The stressed diaphragm is then provided with a flexible suspension 7 at its periphery. This suspension may be employed for securing the diaphragm in position with respect to a driver unit as represented in Figs. 8, 9 and 10 where the stresses remain in the material of the diaphragm stil'l'ening the entire sheet.

In Fig. 8 the process of introducing stresses into the elliptical conical diaphragm has been illustrated more clearly where the pressure forces are applied to the tip of the elliptical diaphragm 3, resulting in the division of forces represented at 6.

In Fig. at I have illustrated a flat elliptical sound reproducing diaphragm 8 secured at its center 9 and free floating. The diaphragm 8 in this instance is constructed of thin sheet material having magnetic properties, and a plurality of electromagnets 10 are arranged below the elliptical diaphragm as is more clearly illustrated in Fig. 5, for actuating the diaphragm 8. The electromagnets 10 are provided with 21 suitable permanent electromagnetic system 11, and

the entire electromagnetic driver is mounted 'ithin an elliptical casing 12. Centrally positioned in the rear wall of this casing I provide an adjustable screw threaded member 14: which cooperates with pin member 15 in the center at 9 of the elliptical diaphragm 8, for adjusting the diaphragm with respect to the electromagnetic operating system. The perimeter of the elliptical diaphragm is flexibly suspended on soft pad members 16 supported with respect to the casing 12 and the cover 17. A suitable acoustic horn is mounted in the cover 17 in the ferrule member represented at 18.

In Fig. 6 I have represented the flat elliptical diaphragm in perspective view and shown the theoretical reproduction of sound vibrations by the diaphragm in such manner that much more even volume in the high notes with respect to the low notesmay be secured than with diaphragms heretofore available. The quantity of the reproduced sound is considerably improved over diaphragms heretofore available.

In Fig. 7 I have illustrated a pair of separated supports 19 over which a rubber band 20 has been stretched. By picking this rubber band at various points from the center toward one support it will be observed that,

as the support is approached the vibrations or tones become much clearer and stronger. In a similar manner when a violin bow. is drawn across the strings close to the bridge of the violin rather than near the center of the strings, a clearer tone is produced. This is the result secured in the elliptical construction of diaphragm for such stresses are introduced that an over-amplification of low notes is prevented.

In Figs. 8, 9 and 10 one of the preferred forms of mounting the elliptical conical diaphragm of my invention has been illustrated in which the flexible material 7 is secured over the elliptical frame 21. The frame 21 is supported by arm members 22 with respect to the housing of the electromagnetic 7 driver.

I have found the elliptical conical shaped diaphragm when constructed from thin sheet material for directly reproducing sound, to be very efficient in its operation and practical in construction.

IVhile I have described my invention in certain particular embodiments, I desire that it be understood that modifications may be made and that no limitations upon my invention are intended other than are imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A sound reproducing diaphragm comprising a large direct acting conical diaphragm of mechanically stressed thin sheet material having an elliptical periphery, and a supporting member attached to the periphery of said diaphragm.

2. A sound reproducing diaphragm comprising a large direct acting conical diaphragm of thin sheet stressed material having an elliptical periphery and a flat back member secured to the periphery of said diaphragm.

3. The method of making a sound reproducing diaphragm which consists in for ing a sheet of thin material into the form of a cone having an elliptical periphery and forcing the peripheral edge of said cone into a plane for introducing stresses in the material of said cone.

4. The method of manufacturing a sound reproducing diaphragm which consists in forming a sheet of thin fibrous material into the shape of a cone having an elliptical periphery and forcing said cone bodily against a flat surface for introducing stresses into the material of said cone and maintaining said cone in stressed position.

5 A sound reproducing diaphragm comprising a large direct acting elliptical diaphragmof mechanically stressed thin sheet material, means for flexibly suspending the periphery of said diaphragm, and means for subjecting said diaphragm at its center to mechanical vibration.

6. A sound reproducing diaphragm consisting of a large direct acting sound reproducing diaphragm consisting of a thin sheet of magnetic material having an elliptical periphery, means for supporting the peri hery of said diaphragm for relatively ree vibration, and means for subjecting said diaphragm to mechanical vibration substantially at the center thereof.

'7. A sound reproducing diaphragm of mechanically stressed material having a conical formation and an elliptical periph-.

ery.

In testimony whereof I aifix my signature.

LE. ROY W. STAUNTON. 

